Ashcroft ATE-2 - Handheld Calibrator - Manual (Page 71)

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The target Full Scale Pressure cardinal value and Min and
Max allowable limits will be displayed.
Use a pressure standard to apply target pressure value to a
pressure module. If the pressure standard does not achieve
exactly the target cardinal pressure value, actual target pres-
sure can be edited within the Min and Max limits. This value is
the pressure reading which is displayed on the external pres-
sure calibration standard.
If the cardinal Full Scale Pressure value cannot be achieved
exactly by the pressure standard:
a. Press left and RIGHT ARROWs to position cursor beneath
desired character
b. Press UP and DOWN ARROWs to increment numeric char-
acters
c. When the pressure value displayed on HHC matches the
value displayed on the pressure standard press ENTER
The display will read “Acquiring Cal Data…Wait while system
is busy”. After Full Scale Cal is complete (several seconds)
the screen returns to the Calibration Menu with “Cal Linear-
ity” selected. At this time the operator can proceed with “Ca
Linearity”, return to “Zero Cal”, or “Cal Full Scale”, or save the
Zero Cal & Full Scale Cal by selecting “Apply new cal” and
pressing “ENTER”.
6. Select “Cal Linearity” and press “ENTER”.
When calibrating linearity, the HHC will automatically choose
the number and pressure value of data points based on the
module’s full scale pressure range and its base accuracy
specification. The number of equidistant pressure values
required for linearity calibration is listed below:
0.025% & 0.05% enhanced accuracy
20 points (approximately 10% increment)
0.025% - 0.07% standard accuracy
11 points (approximately 10% increment)
0.1% standard accuracy
6 points (approximately 20% increment)
0.25% standard accuracy
5 points (approximately 25% increment)
The first linearization point target pressure and min and max
allowable limits in default engineering units will be displayed.
Using the pressure standard, apply the target pressure to the
module. If the pressure standard does not achieve exactly
the target cardinal pressure value, actual target pressure can
be edited within the Min and Max limits. Actual value is the
pressure reading which is displayed on the external pressure
calibration standard.
If the cardinal linearization pressure value cannot be achieved
exactly by the pressure standard:
a. Press left and RIGHT ARROWs to position cursor beneath
desired character
b. Press UP and DOWN ARROWs to increment numeric
characters
7. When the pressure value displayed on HHC matches the value
displayed on the pressure standard press ENTER” The system
will respond with “Acquiring Cal Data…Wait while system is busy”.
NOTE: The first linearization point pressure is equivalent
to the first pressure point after Zero for all pressure types,
except Compound. For the Compound ranges, the first cali-
bration point will be an equivalent to the lowest negative pres-
sure of the range.
Upon completion of the first calibration point inquiry, the HHC
will respond with a next calibration point screen and continue
through the process until the last calibration point is complete.
The last calibration point will be a pressure point one step
before the Full Scale pressure. Repeat steps 6 and 7 as many
times as required based on accuracy as noted above.
SECTION 15 o. PRESSURE MODULE CALIBRATION
CONT.
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